Oral Presentation Australian Society for Fish Biology & Australian Freshwater Sciences Society Conference 2026

Mapping Walking Sharks: Updated distributions and a new species described from Papua New Guinea (144523)

Jessica Blakeway 1 , Mark Erdmann 2 , Gerald Allen 3 , Max Teliwa 4 , Julie Anne Waranaka 5 , Kathy A Townsend 1 , Christine L Dudgeon 1
  1. Science Technology and Engineering, The University of the Sunshine Coast, Moreton Bay, QLD, Australia
  2. RE:wild, Austin, Texas, USA
  3. Department of Aquatic Zoology, Western Australian Museum, Welshpool, Western Australia, Australia
  4. District Fisheries, Milne Bay Provincial Administration, Alotau, Milne Bay, Papua New Guinea
  5. The University of Papua New Guinea, Port Moresby, Papua New Guinea

Hemiscyllium is a genus comprising nine species of small, benthic-dwelling sharks, commonly referred to as "walking sharks" that are endemic to northern Australia, the island of New Guinea, and its satellite islands. Of these, five species are currently classified as threatened, including three species endemic to Papua New Guinea (PNG)1. Despite their conservation status, there are no local or national species-specific protections for walking sharks in PNG, and limited data exist to inform effective management, particularly regarding species distributions2.

Walking sharks are characterised by non-overlapping, small geographic distributions and site-associated individual ranges typically spanning only a few hundred meters to a few kilometres. These traits, coupled with limited dispersal abilities, suggest that populations may be genetically distinct but also highly vulnerable to localised disturbances and even extirpation3.

This study presents findings from a series of in situ surveys aimed at reassessing the distributional limits of walking sharks in PNG. We employed genetic analyses of genome-wide single nucleotide polymorphisms (SNP) and the mitochondrial NADH-4 gene to assess the taxonomy of updated distributions and delineate species boundaries. 

Here we present a newly described species, Dudgeon’s walking shark (Hemiscyllium dudgeonae). Additionally, we present a concept of a mosaic of disjunct, non-overlapping distributions previously unreported for this genus associated with updated ranges for Hemiscyllium michaeli and Hemiscyllium hallstromi. 

  1. 1. Allen, G. R., Erdmann, M. v, White, W. T., Fahmi, & Dudgeon, C. L. (2016). Review of the bamboo shark genus Hemiscyllium (Orectolobiformes : Hemiscyllidae). Journal of the Ocean Science Foundation, 23, 51–93. https://doi.org/10.5281/zenodo.164197
  2. 2. VanderWright, W. J., Dudgeon, C. L., Erdmann, M. v, Sianipar, A., & Dulvy, N. K. (2022). Extinction Risk and the Small Population Paradigm in the Micro-Endemic Radiation of Epaulette Sharks. Imperiled: The Encyclopedia of Conservation, 752–762. https://doi.org/10.1016/B978-0-12-821139-7.00130-6
  3. 3. Erdmann, M. v, & Dudgeon, C. (2024). Spotlight on Highly Threatened Groups: Walking (epaulette) sharks. In R. W. Jabado, A. Z. A. Morata, R. H. Bennett, B. Finucci, J. R. Ellis, S. L. Fowler, M. I. Grant, A. P. Barbosa Martins, & S. L. Sinclair (Eds.), The global status of sharks, rays, and chimaeras (pp. 2053–2066). International Union for Conservation of Nature and Natural Resources. https://doi.org/10.59216/ssg.gsrsrc.2024